Can opener



Oct. 3, 1961 W. W. EDLUND CAN OPENER 2 Sheets-Sheet 1 Filed NOV. 21,1958 Oct. 3, 1961 w. w. EDLUND CAN OPENER 2 Sheets-Sheet 2 Filed Nov.21, 1958 j" V INVENTOR 2/4159? 1. I'd/11nd 4755.7

BY z I I United States Patent O 3,002,275 CAN OPENER Walter WrEdlund,Burlington, Vt. Filed Nov. 21, 1958', Ser. No. 775,409 Claims. (Cl.30-9) This invention relates to improvements in can openers andparticularly to a manually operated heavy duty can opener adapter foruse in restaurants and other commercial establishments. These heavyduty. openers having manually operated crank handles have been employedin such establishments for many years and have received rather wideacceptance. Such can openers are of two general types in so far as theiroperation is concerned, namely: The two handle type which requires theoperation of two handles in effecting the opening and release of thecan, and the single handle operated type. The latter are preferable fromthe users standpoint but have heretofore been provided with straightedge knives. Such knives are not as satisfactory as disc knives.However, no one has heretofore devised a satisfactory disc knife singlehandle opener. One object of this invention is to provide a single leveroperated manual can opener employing a rotary knife.

Heretofore known can openers of the type to which the present inventionrelates, embodying disc cutters, are at a disadvantage in that thecutters require adjustment from time to time and that the cutters whenin cutting position are fixed with respect to the gears or other meansemployed for propelling the can. Another object of the instant inventionis to provide an opener in which adjustment of the cutting blade withrespect to the propelling means is unnecessary and a further object isto provide an opener in which the cutting blade is resilientlypositioned. This latter advantage will prevent damage and insures aneasier operation.

A further object of the invention is to provide a can opener as setforth in the preceding objects embodying a casting which has a cleanexterior, is relatively simple and compact and can be relatively easilyand cheaply cast. Heretofore known castings providing the main housingsfor the openers are relatively complex and do not provide a neatexterior.

A further object of the invention is to provide a can opener which isreadily and economically adaptable to an exterior formation which willresult in a pleasing appearance for the opener. Heretofore known canopeners of the instant type embodied projections and attachments orscrews or other devices which detracted from the appearance andmilitated against the formation of a clean neat modern design opener.

A still further object of the instant invention is to pro- I vi-de anopener including a housing structure which substantially completelyencloses the opener and in which the housing construction is neat, cleanand free from projections.

Another advantage of such construction as set forth in the precedingobjects is to provide an opener which will remain clean, which is lesslikely to pick up dirt, foreign particles, etc., and which also can beeasily cleaned in the event such particles should be received therein.

A further object ofthe instant invention is to provide an opener as setforth heretofore which does not require attachments for completing thecasting or forming can stops or other means and in which, instead, aunitary casting is employed and the stop means for positioning the canare formed integrally therewith.

It is well known that it is necessary and customary to move the knifeutilized in cutting the can, with respect to the means for impelling thecan past the knife, so as to insert and remove the can from the opener.One

new

of the two handles mentioned above as used with prior known openers isprovided for this purpose. The latter handle controls swinging movementof the knife with respect to the impelling means, usually a gear, andthe usual crank handle is provided for rotation of the gear likeimpelling means, once the knife is in cutting position. With such anopener the hand of the operator must be shifted from the knife movingmeans to the impeller operating means and back to perform a completecutting operation, including insertion and removal of the can orconnection and disconnection of the can from the cutter. Accordingly oneof the objects of the instant invention is to provide a one-handoperated opener having only one lever or its equivalent whereby theother hand of the operator or user of the device is free formanipulation and placement of the can with respect to the opener, etc.

An additional object of the invention is to provide a one-hand operatedopener having an operating handle which functions to rotate the canimpelling means together with means operated by the same handle formoving the cutter with respect to the can impelling means.

Still another object of the invention is to provide an openeraccomplishing the foregoing objects wherein the connection between thecutter and the impelling gear means is such that the opener can beeasily operated both during normal cutting and in the connection anddisconnection of the can and opener.

A further object of this invention is to provide an opener constructionwith which cans can be readily inserted into cutting relationship withthe opener with much greater ease than heretofore possible.

An additional object of the invention is to provide an opener as setforth in the preceding object with which eiiective proper cuttingcontact with the can is achieved by simply bringing the can into bearingrelationship against a portion of the opener andv the opener is thenbrought downwardly onto the can. Through a continued downward movementof the opener the can is received in proper cutting relationship and thecutter is properly engaged with the can. With the heretofore knownapparatus of a similar type if the can cutting or puncturing mechanismis not properly positioned the can is apt to hang up on the opener asthe latter is brought down into a cutting relationship with the can.This cannot occur however withthe instant construction since, due to thesingle handle operating structure, proper relationship of the cuttingknife to the can for puncturing is assured when the opener is raised.

It is also noted that with heretofore known constructions the cans mayhang up even if the puncturing rnechanism is properly positioned forinsertionuof the can.

A further object is to insure that this will not occur; that once theopener is raised the cutter and can impeller are properly positioned andthat the opener can then be simply brought down onto the can.

One other object of the invention is to provide a resiliently positionedcutter which can accommodate to irregularities and which is properlymaintained in cutting position.

These and other objects and advantages will become apparent from thefollowing description and the accompanying drawings in which:

FIGURE 1 is a side elevational view of an opener constructed inaccordance with the invention.

FIGURE 2 is a front elevational view.

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 2 showingthe elements in can opening position.

FIGURE 4 is a view similar to FIGURE 3 but showing the parts in adifferent relationship.

FIGURE 5 is a sectional view taken along line 55 of FIGURE 3.

FIGURE 6 is a sectional view taken along line 6-6 of FIGURE 3.

FIGURE 7 is a bottom view partly in section of a I knife holder takenalong line 77 of FIGURE 3.

FIGURE 8 is a top sectional view taken in the direction indicated byline 88 of FIGURE 3 and showing a support.

FIGURE 9 is a side elevational view of the opener in position in itssupporting base and showing a can, which is being placed in position forcutting, initially striking a stop.

FIGURE 10 is a sectional side elevational view similar to FIGURE 9 butshowing the can as it moves upwardly along the stop into cooperationwith the knife.

FIGURE 11 is a View similar to FIGURE 10 but showing the can and openerin cutting position.

Referring now in particular to the drawings:

A can opener constructed in accordance with the instant invention has ahousing 10. The latter comprises a pair of spaced side walls 12 and 14,and a connecting wall 16. The latter wall forms the rear 18 and top 28of the housing. A front bridging wall 22 is positioned adjacent thefront of the housing and also interconnects the side walls 12 and 14.The front bridging wall 22 extends practically half way up the front ofthe housing. The front wall 22 also merges at its bottom into a support24. In the preferred embodiment this is a post of the type that has beenknown in the art and utilized to adjustably attach the opener to aplatform or base. In FIGURE 9 the co-operation of the post and its baseis illustrated. Similar structure is also shown in Patent No. 1,537,110to Walter W. Edlund dated May 19, 1925 and Edlund Patent No. 1,713,823dated May 21, 1929. The walls 12, 14, 16 and 22 define a chamber 26having an upper and forward opening 28, and a lower rear opening 30. Theopener housing It} is preferably formed of a casting with all the abovedescribed walls being integral. Further, preferably the post 24 is alsoformed as a casting integral with the housing 10. However, it isapparent that the post 24 or other support means can be connected to thehousing 10 by other suitable means such as is known in the art and alsothat the housing can be formed by other methods.

The front wall 22 has a stepped opening 32 comprising a first chamberhaving a shoulder 34, a connecting bore having a shoulder 36 and a thirdbore 38 connecting to the second bore. The bored openings providing theshoulders 34, 36 and the bore 38 are preferably aligned and are allconcentric of a single axis. A stepped bushing 40 is received in thebore 38 and bears against the shoulder 86. Preferably there is a tightfit between bore 38 and the bushing. The bushing occupies all of thethird bore and stepped opening providing the shoulder 36. The bushinghas a preferably central shaft receiving opening 42. The rear wall 18 ofthe housing 18 has 2 preferably cylindrical opening 44 the axis of whichis aligned with the axis of the bore 42. A bushing 46 is slidablyreceived within the opening 44, and an arbor 48 extends through an arborreceiving opening 50 in the bushing 46 and the arbor opening 42 in thebushing 48. The arbor is rotatably received in both bushings. The arboris preferably stepped to provide a rear arbor portion 52 and a frontarbor portion 54, as well as a shoulder 56. The shoulder 56 bearsagainst the shoulder 58 of the stepped bushing 40. The front arborportion 54 projects forwardly of the bushing 40 and the front bridgingwall 22, and that portion which does so project forward is threaded asindicated by reference character 61?. A gear wheel 62 having peripheralteeth 64 is threaded onto this projecting portion into abutment with thebushing and closely adjacent the front face of the wall '22.

Substantially all of the gear is received within the recess.

65 provided by the side walls 12, 14 and the front wall 22.Substantially only the upper portion of the gear projects forwardly ofthe housing walls 12 and 14. At its rear the arbor is provided with atransversely extending pin 66 and is formed so as to provide a pair ofparallel shoulders 68 and 70. The handle 72 has a bifurcated end 74which closely fits with the shoulders 68 and 70 and receives the pin 66in a manner such as to pivotally mount the handle for pivotal movementabout an axis extending transversely of the arbor 48. The bifurcated endportions of the handle are provided with a pair of shoulders 76 and 78adapted to bear against the bushing 46. The shoulders 76 and 78 arepositioned at different radial distances from the center of the pin 66and the handle as mentioned above is pivotal about this pin. Further,the shoulders 76 and 78 are at right angles to each other and the handlecan be rotated through degrees from a position in which the shoulder 76bears against the bushing 46 to a position in which the shoulder 78bears against the rear wall of the bushing 46. As a result the bushingin order to accommodate this movement must be capable of movement alongthe arbor 48, and a free sliding fit is preferred between the bushing46, the arbor 48, and the housing 10. The bushing is normally maintainedin the position illustrated in FIGURE 3 by resilient means hereinafterdescribed, but will move to the position illustrated in FIGURE 4 whenthe handle is rotated in the direction indicated by the arrow 80.

A knife holder 82 is received in the housing 10. This knife holdercomprises a front wall continua-tion portion 84 which is normallyadapted to present the appearance of a continuation of the frontbridging wall 22 upwardly to the top of the housing. Wall portion 84normally closes the inner chamber 26 adjacent its upper end preventingthe entrance of dirt, etc. The knife holder further comprises arearwardly extending portion 86 and a forwardly projecting boss 88. Theforwardly projecting boss extends downwardly at an angle ofapproximately 41 degrees with respect to the front wall continuationportion and is turned with respect to the vertical plane containing thearbor 48 so that it extends forwardly thereof toward the feed-in side 89of the opener at an angle of approximately 7 degrees. As illustrated inFIGURE 3 the rearwardly extending portion 86 extends at an angle ofapproximately 90 degrees with respect to the front Wall continuationportion 84. The feed-in side is to the right side of the cutter inFIGURE 2, and is the side from which the can rotates toward the cutter.

A bifurcated arbor receiving portion 90 projects downwardly from therear of the rearwardly extending portion 86 of the knifeholder 82. Thelegs Q2 and 94 of portion 90 project down on opposite sides of and thusreceive the arbor 48. The knife holder 82 is pivotally mounted withinthe housing 10 by means of a shaft 96 which is formed of a rivetextending transversely through the side walls 12 and 14. The knifeholder is readily pivotal on the shaft 96. The legs 92 and 94 in thenormal position of the knife holder 82, which is the positionillustrated in FIGURE 3, extend substantially transversely across thearbor and present forward faces against which is positioned a washer 98.A like washer 100 is positioned against the shoulder 34 within therecess there adjacent. A compression spring 102 extends between the twowashers and normally urges pivotal movement of the knife holder throughthe medium of the bifurcated portion 90, counterclockwise about theshaft 96. This movement is limited to that. in which the front wallcontinuation portion 84 extends substantially parallel to the frontedges of the side walls 12 and 14 by means of a shoulder 104 whichextends across the'top of the front bridging wall 22 and a matingshoulder 106 which is formed by the lower edgeof the boss 88. The loweredge of the boss 88 and the wall portion 84 substantially join eachother in the plane of shoulder 106. Shouider 184 slopes toward the frontof the housing and is substantially parallel to the boss 88 when thelatter is in the position illustrated in FIGURE 3.

The rear of the'legs 92 and-94 are provided with-raised cam likevertically curvilinear shoulders 108 and 110 respectively. These arenormally urged by the spring 102 into contact with the bushing 46. Thepants are in the relative position illustrated in FIGURE 3 when the canopener elements are in normal operating position with a can receivedbetween the gear wheels and cutter, or when the opener is merely atrest. The spring 102 normally maintains this relative positioning of theparts.

The boss 88 provides a front shoulder 112. The rear of the knife holderis formed so as to provide a shoulder 114 parallel to the shoulder 112and also to provide a recess 116.

A knife holder shaft 118 extends through a bore 120 substantiallyperpendicular to the shoulders 112 and 114. The shaft has a reducedforward end 122 and a reduced rearward end 124. The latter end isthreaded. The length of the central portion 126 is substantially thesame as that of the shaft receiving opening 120. A disc knife 128 ismounted on the forward reduced end 122 and abuts against the shoulder112 of the boss 88 and the central portion 126 of the shaft. The knifeis held in place by a retaining ring 129. The knife has a can lipreceiving peripheral groove 130.

A washer 132 is received on the rearward reduced end 124. A spring 134bears against this washer and a lock nut 136. Nut 136 maintains theparts in assembled re-- lationship. The spring 134 urges the knife andshaft resiliently against the shoulder 112.

When the elements are in normal operating position t e gear wheel rimprojects into the lip receiving groove, but is spaced therefromsufficiently to receive the lip of a can, and the blade extendsdownwardly into the top of the can as illustrated in FIGURE 11. Theupper wall 20 is provided with a depending bead 138 which extendsdownwardly toward the front wall .continuation portion 84 of the knifeholder 82 to cooperate with the latter to close the inner chamber 26.

The housing is provided with a pair of stops or rests 140 and 142. Thestop or rest 140 consists of a projection laterally of the front face ofthe side wall 12 forming a forward surface substantially co-planar withthe latter. The stop 142, on the contrary, in addition to constituting aportion extended laterally of the vertical surface of the front edge 146of the side wall 14 has an outward projection extending outwardly of theforward edge 146 and defining a contact surface 144. The surface 144defined by the stop 142 is substantially parallel to the shoulders 34,36 and the front shoulder 148 of the front bridging wall 22 and extendsupwardly substantially in horizontal alignment therewith alongside thegear wheel 62. The surface 144 is started low enough on the side wall 14so that the surface 144 extends outwardly forwardly of the opener to adistance substantially in alignment with the maximum forward projectionof the upper end of the gear wheel. Note that the gear wheel presents atits front a frustoconical shape 150 and thus only its upper portionprojects forwardly of the surface 144. The surface 144 merges with thefront edge 146 and also merges with the front edge 152 of the post 24.The shoulders 140 and 142 guide the cam during its rotation relative tothe opener and further as is apparent from an examination of FIGURES9-11 serve to guide the can into proper cutting. position.

FIGURE 9 illustrates the relative position of the opener and its post 24with respect to the base 154. The latter is a type which has beenemployed heretofore in mounting these heavy duty can openers. It isapparent that the opener is adapted to take a number of sizes of cans.

In opening a can the following steps are performed: The handle '72 whichis noted has a rotatable knob 156 is swung counter clockwise asindicated by the arrow 80 and subsequent thereto the post and head aremoved upwardly with respect to the base. This movement of the handlecauses a clockwise rotation of. the knife holder which raises the :knifefrom the zgeal. The can is then inserted beneath the opener and againstthe surface 152 of the post. After which the postand opener are moveddownwardly. When they are in the position indicated in FIGURE 9 the canstrikes the stop and positioning surface 144 so that continued downwardmovement of the opener urges the can away from the opener on the feed-inside. This'causes the canto clear the gear Wheel 62. It is noted thatthe knife is in the position illustrated in FIGURE 4 and the can bead isthus camrned upwardly into connection with the knife. In FIGURE 4 thecan is illustrated adjacent the top of the stop with the rim havingentered into the rim grove 13th The knife now rests on the can cover.Next the handle is swung downwardly into the position in which it isillustrated in FIGURE 3. As this is done the elements including the canrim assume the relative positioning illustrated in FIGURE 10 with theknife still pressing against the can top, "but also pressing the canhead against the gear. Note that the can side is also pressed againstthe gear face.

Now upon rotation of the handle the knife will snap into cuttingrelationship and the elements will take the position illustrated inFIGURE 11. A distinctly audible snap is head as the knife initially cutsinto the can. In this position the can rim bears against the stops and142. Upon continued rotation the rim is moved across the teeth of thegear wheel 62 and the top is thus severed by the knife. The springs 134and 102 resiliently maintain the cutter in proper position but enableautomatic adjustment to any irregularities.

With this construction it is never necessary to keep adjusting thecutter Wheel. Further, different sized and shaped cans are allaccommodated with the one setting.

When the can opener has completed its can opening operation it isapparent that the handle is moved upwardly and at the same time the headis raised. All this can be accomplished while holding the can inposition, thus preventing spilling. and facilitating instant detachmentof the can from the opener.

The stop' construction and knife and gear wheel relationship therewithfacilitates placement of the cans. It is only necessary to slide the canup against the post 24 and lower the opener in order to obtain a correctpositioning of the can. The can will always be crammed into propercutting position. This is an obvious advantage over openers where suchconstruction is not provided. Note that the cutting edge of the cutter128 extends outwardly a substantial distance relative to the gear wheeland shoulder 144- as the opener is being moved down along the can andthe rear edge 158 of the knife which is a beveled edge will cam the canrim head into proper relationship to be properly engaged by the gearwheel and cutter. It is only necessary, as pointed out hereinbefore, toswing the handle of the opener down after the can has been insertedbeneath the opener and then crank the handle and the cutting of thecover will be effected.

While I have shown and described a preferred form of my invention itwill be apparent that many changes in details and form can be made, andtherefore I claim anexclusive right to all modifications and changes inform coming within the scope of the appended claims.

I claim:

1. A can opener comprising a housing, said housing having a chamber, abridging wall positioned in said chamber adjacent one side thereof, saidhousing having a front face formed by a pair of side walls, saidbridging wall being adjacent said front face and being inclined withrespect thereto in a vertical plane, said bridging wall and said housingdefining a recess, a gear wheel rotatably received in said recess andhaving an upper portion of its periphery projecting outwardly of saidfront face with its lower portion being received to the rear of said.front face within said recess, a knife holder positioned in saidchamber, a knife Supported by said knife holder and normally projectingoutwardly of said front face, said knife being in relationship with saidgear wheel for receiving a can therebetween for severing a portion ofsaid can, said knife holder normally bearing on said bridging wall andextending laterally Within said chamber substantially intermediate thetwo side walls adjacent said front face and having an upstanding portionforming a continuation of said front face in a vertical plane upwardlyabove said bridging wall but being spaced from said side walls of saidhousing sufiiciently for movement of said knifeholder with respectthereto, means for moving said knife holder and the knife connectedthereto with respect to said gear wheel for the insertion and removal ofa can therebetween.

2. A can opener comprising a housing, a gear wheel rotatably supportedon said housing, said housing having a front face, said gear wheelhaving the upper peripheral portion thereof projecting outwardly of saidfront face, a rotary knife means cooperable with said gear wheel foropening a can with said gear wheel and knife having cooperating recessmeans for receiving a can portion therebe-tween, a pair of stop meanspositioned laterally on opposite sides of said gear wheel, one of saidstop means being positioned on the feed in side of said gear wheel andknife and the other being positioned on the feed out side, the stop onsaid feed in side defining a planar surface angling vertically withrespect to said front face of 'said housing, the upper portion of saidsurface terminating at approximately the height of said can receivingrecess means defined by said gear wheel and said knife, said surfaceextending throughout its length a distance from said face sufficient tourge a can rim moving vertically upward thereagainst outwardly withrespect to said gear wheel on said feed in side of said wheel.

3. The apparatus of claim 2 wherein said housing is supported on a postslidably positioned within a base member, said post having a front facedisposed substantially in the same vertical plane as the front face ofsaid housing with said feed in side stop projecting outwardly of saidplane forwardly thereof with respect to said housing and post andmerging with said front face of said housing at its base, an arbor, saidgear wheel being mounted on said arbor, said front face of said stopextending substantially perpendicularly to the axis of said arbor andsaid gear wheel.

4. The apparatus of claim 2 wherein said knife means is movable withrespect to said stop substantially laterally alternately outwardly andinwardly with respect to said front face and sufficiently to alternatelyopen said recess to receive a can bead therein as the latter moves abovesaid stop and alternately press said gear bead against said wheel.

5. A can opener comprising a housing, said housing having an upper frontopening and a lower rear opening, a pair of side walls and a memberforming a continuous upper wall and rear wall interconnecting said sidewall, a bridging wall positioned adjacent the front of said housing anddefining in part said upper front opening, said bridging wall having afront surface, a gear wheel bearing against said front surface, an arborconnected to said gear wheel and extending through said bridging walland said rear wall of said housing, means for rotating said arbor, aknife holder movably mounted within said housing and having a cuttingwheel cooperable with said gear wheel for opening a can, said knifeholder having an upstanding front wall continuation portionsubstantially closing said upper opening in said housing during normalcutting of a can, said knife holder being movable with respect to saidgear for insertion and removal of a can intermediate said gear and aknife supported on said knife holder.

6. A can opener comprising a housing, a can-engaging gear positioned insaid housing and having a portion projecting upwardly thereof forengagement with a can positioned against said housing, a knife holder,said knife holder having a shaft slidably positioned therein, a kniferotatably mounted on one end of said shaft and bearing against saidknife holder, resilient means connected to the other end of said shaftand said knife holder resiliently urging sliding movement of said shaftin said knife holder, said gear having an arbor connected thereto, saidarbor and said shaft being positioned at an acute angle with respect toeach other, said knife holder and arbor being substantially receivedwithin said housing and said knife holder having a portion thereofextending between spaced walls of said housing above said gear andforming a continuation of said housing, and means for rotating saidarbor.

7. A can opener comprising a housing, a can-engaging gear positioned insaid housing and having a portion projecting upwardly thereof forengagement with a can positioned against said housing, a knife holder,said knife holder having a shaft slidably positioned therein, a kniferotatably mounted on one end of said shaft and bearing against saidknife holder, resilient means connected to the other end of said shaftand said knife holder resiliently urging sliding movement of said shaftin said knife holder, said gear having an arbor connected thereto, saidarbor and said shaft being positioned at an acute angle with respect toeach other, said knife holder and arbor being substantially receivedWithin said housing and said knife holder having a portion thereofextending between spaced walls of said housing above said gear andforming a continuation of said housing, and means for rotating saidarbor, said housing including a bridging wall, said gear beng mountedadjacent said bridging wall, said bridging wall defining an uppersupport, said knife holder resting on said upper support, a resilientmeans urging said knife holder to pivot with respect to said gear, saidupper wall surface constituting means for resisting said pivotalmovement.

8. A knife holder for a can opener comprising a housing, a first shaftopening extending through said housing, a second shaft opening extendingthrough said housing laterally of the first mentioned shaft opening,said housing having a pair of depending legs extending downwardlyadjacent one end of said housing and spaced apart to receive a canopener operating shaft, an upstanding wall portion extending upwardlyfrom said housing in a direction substantially opposite the direction ofextension of said legs and adapted to form a portion of an openerhousing, boss means on said housing adjacent and concentrically disposedwith respect to said first shaft opening and adapted to bearinglycontact a rotany knife element.

9. The apparatus of claim 8 including a shaft supported in said firstshaft opening, resilient means bearing against said housing and saidshaft and urging movement of said shaft longitudinally of said bore, arotary knife ele ment rotatably fixed on said housing by said shaft,said knife element being resiliently urged against said boss means bysaid resilient means and having a peripheral cutting edge lying in aplane extending transversely of said shaft.

10. In a can opener, a housing for an operating mechanism, said housingcomprising a pair of spaced side walls, a connecting wall connectingsaid side walls along a portion thereof and forming a rear and top wall,a bridging wall extending substantially parallel to said rear wall andfrom adjacent one edge of said side walls to the bottom thereof, saidside walls forming a front face, said connecting wall extending at anangle to said front face of approximately 15 degrees, post meansconnected to said bridging wall and said side walls, said bridging wall,said side walls and said connecting wall forming a chamber having anupper forward opening and a lower rear 9 opening, means forming alignedopenings in said bridging 2,361,561 wall and said rear wall forsupporting an arbor. 2,383,929 2,403,959 References Cited in the file ofthis patent UNITED bTATES PATENTS 274,531 1,986,870 West Ian. 8, 1935 4334 10 l Mueller et al. Oct. 31, 1944 Landry Aug. 28, 1945 Simmons July16, 1946 FOREIGN PATENTS Italy May 23, 1930 Italy June 14, 1948

